The proposed study is in preparation for the planning of a complex epidemiologic prospective investigation on nutrition and chronic diseases incidence and mortality. In this inquiry we plan to: A) Generate a data-based food frequency questionnaire from nutrition data already collected with extensive dietary methods (food diaries of weighed intake, and dietary histories). B) Examine the validity of the developed food frequency questionnaire by comparing it with more extensive dietary methods (food diaries of weighed intake and dietary histories). C) Perform a trial mailing of the food frequency questionnaire in a subsample of 500 individuals randomly selected from the cohort to be followed. The following are important characteristics of the future complex prospective epidemiological investigation in which we plan to use the dietary instrument to be developed with the methodology described in this proposal. A) The population to be followed is composed of Italian men who are members of an army veterans organization and residing in various regions of Italy, a country with distinct regional dietary patterns. This wide variation of dietary pattern within a single culture will allow us to overcome a major methodological problem of epidemiological nutritional studies, that is, the relative lack of variation in the consumption of certain nutrients within most single cultures. B) Other advantages include the possibility of collecting data on both cancer and cardiovascular disease incidence through a number of tumor registries and through the monitoring procedure of the MONICA project (see Figure 1 for their locations). (The MONICA project is a World Health Organization sponsored multinational project for the monitoring of the trends and determinants of cardiovascular disease.) C) Use of veterans of the Alpine troops offers the possibility of organizing an unselected cohort (the military draft is mandatory in Italy) that is characterized by strong cohesiveness and that has shown already willingness to cooperate by providing additional resources for complete follow-up of the cohort.